ML070880565

Response to Request for Additional Information Regarding an Alternative for the Weld Overlay of Pressurizer Nozzle Welds

ML070880565
Person / Time
Site:	Millstone
Issue date:	03/28/2007
From:	Gerald Bichof Dominion, Dominion Nuclear Connecticut
To:	Document Control Desk, NRC/NRR/ADRO
References
07-0116, TAC MC3379
Download: ML070880565 (40)

Text

Dominion Nuclear Connecticut, Inc.

5000 Dominion Boulevard, Glen Allen, Virginla 2.1060

\ct> Addresc: www.dom.com March 2 8 , 2007 U. S. Nuclear Regulatory Commission Serial No. 07-01 16 Attention: Document Control Desk NL&OS/PRW RO One White Flint North Docket No. 50-423 11555 Rockville Pike License No. NPF-49 Rockville, Maryland 20852-2738 DOMINION NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION UNIT 3 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING AN ALTERNATIVE FOR THE WELD OVERLAY OF PRESSURIZER NOZZLE WELDS (TAC NO. MC3379)

In a letter dated October 17, 2006, Dominion Nuclear Connecticut, Inc. (DNC) submitted Alternative Request IR-2-47 requesting approval for the use of weld overlays as an alternative for repairs to pressurizer nozzle welds for Millstone Power Station Unit 3 (MPS3). In a facsimile dated February 8, 2007, the NRC forwarded a draft request for additional information (RAI) in order to clarify certain items in DNC's proposal. The response to the NRC's questions is provided in Attachment 1 to this letter. Request IR-2-47, Revision 1 is provided as Attachment 2 of this letter. Enclosure 1 of Attachment 2 replaces Code Case N-740 with DNC's alternative requirements for dissimilar metal weld overlays.

Should you have further questions, please contact Mr. Paul R. Willoughby at (804) 273-3572.

Very truly yours, Gerald T. Bischo /"

Vice President - Nuclear Engineering

Serial No. 07-01 16 Docket No. 50-423 Response to Request for Additional Information Page 2 of 2 Commitments in this letter: None Attachments: (2)

Attachment 1: Response to Request for Additional lnformation Attachment 2: Alternative Request IR-2-47, Revision 1 Use of Weld Overlays as an Alternative Repair Technique

Enclosure:

Enclosure 1: Alternative Requirements for Dissimilar Metal Weld Overlays cc: U.S. Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, PA 19406-1415 Mr. V. Nerses Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Mail Stop 8C2 Rockville, MD 20852-2738 Mr. S. M. Schneider NRC Senior Resident Inspector Millstone Power Station

Serial No. 07-0116 Docket No. 50-423 ATTACHMENT I ALTERNATIVE FOR THE WELD OVERLAY OF PRESSURIZER NOZZLE WELDS RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION DOMINION NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION UNIT 3

Serial No. 07-01 16 Docket No. 50-423 Response to Request for Additional Information Attachment 1 page 1 of 13 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION In a letter dated October 17, 2006, Dominion Nuclear Connecticut, Inc. (DNC) submitted for staff review and approval Alternative Request IR-2-47 for the weld overlay of pressurizer nozzle welds at Millstone Power Station Unit 3 (MPS3). To complete its review, the NRC staff forwarded a draft request for additional information (RAI) in order to clarify certain items in DNC's proposal. The response to the NRC's questions is provided in the balance of this attachment.

Unless otherwise indicated, references to Enclosure 1 in DNC responses to the RAI questions mean Enclosure 1 of this letter.

Questions on Request IR-2-47 in Attachment I to the October 17, 2006 letter NRC Question 1 The NRC has not approved Code Case N-740 in Regulatory Guide 1.l47, Revision 14 (the latest revision). Therefore, the staff is not able to review the submittal per Code Case N-740. The staff has approved Code Cases N-504-2 and N-638-1 which provide requirements for the weld overlay design. The staff requests the licensee to provide a crosswalk and explain the differences between requirements in Code Cases N-504-2 and N-638-1 and proposed Request IR 47 which is based on Code Case N-740.

DNC Response DNC recognizes that Code Cases N-504-2 and N-638-1 are conditionally approved in Regulatory Guide 1.147, Revision 14. However, Code Case N-504-2 can not be used directly without modifications to address the austenitic nickel alloy weld overlay materials. Similarly, modifications would also be required for specific weld overlay applications for temper bead welding in N-638-1.

In a letter dated October 17, 2006, Alternative Request IR-2-47 was submitted as noted above, and Enclosure 1 to Attachment 1 of that letter provided a copy of ASME approved Code Case N-740. Code Case N-740, with some slight modifications, was believed at that time to cover the desired technical attributes for an acceptable weld overlay constructed with austenitic nickel materials.

Since the time of that submittal, flaws identified in weld overlay applications at one plant and flaws found by examination in existing pressurizer welds at another plant have heightened concerns in the industry regarding weld overlay applications for mitigation of primary water stress corrosion cracking (PWSCC).

In a public meeting January 10, 2007, NRC concerns with N-740 were presented by the staff and discussed with industry representatives. ASME Section XI representatives at the meeting stated that ASME would review the concerns and

Serial No. 07-0116 Docket No. 50-423 Response to Request for Additional Information Attachment 1 page 2 of 13 propose the necessary changes to Code Case N-740. During the week of January 29, 2007, through February 2, 2007, ASME held meetings in which changes were made to Code Case N-740. The proposed changes are now under final approval within ASME.

Considering recent industry efforts to revise Code Case N-740, Request IR-2-47 has been revised with a set of alternative criteria provided in Enclosure 1 of of this letter. The new Enclosure 1 provides the necessary additional information to answer the NRC RAI questions as cited in the balance of this response.

NRC Question 2 In Section 2.0 of Alternative Request IR-2-47, the licensee stated that "...The additional examination requirements of the RI-IS1 [risk informed inservice inspections] program and MRP-139 will be met with application of these five PWOLs...". (A) Clarify whether the IS1 of the weld overlaid pressurizer nozzles would be based on the requirements of the proposed alternative request IR-2-47, the RI-IS1 program, or MRP-139. (6) Discuss whether the subject nozzles have been ultrasonically examined under the RI-IS1 program or MRP-139 in previous refueling outages. If so, discuss whether flaws have been detected in the subject nozzles.

DNC Response (A) Inservice examination requirements for preemptive weld overlays (PWOLs) applied in accordance with this alternative will meet the requirements in Attachment 2, Enclosure 1, Section 3 (c).

(6) None of the pressurizer welds addressed in Request IR-2-47 have been ultrasonically examined to meet the requirements of the RI-IS1 Program or MRP-139 during previous outages. Ultrasonic examination (UT) of the welds was performed in refueling outage 3R10 in the fall of 2005 in accordance with DNC's commitment to NRC Bulletin 2004-01 for MPS3. Spray nozzle weld 03-X-5641-E-T was weld overlay repaired along with its adjacent safe end-to-pipe weld. Examination of this nozzle-to-safe end weld had no reportable indications using a performance demonstration initiative (PDI) UT. The UT examination was performed for axial indications only. Radiography (RT) was performed to ensure coverage for circumferential indications due to the as-found field condition weld crown. This RT examination revealed circumferential indications which led to machining the weld flat and performing an automated UT which achieved 100% coverage for the indications in both directions. Indications, evaluated as fabrication flaws (not connected to the ID), were detected and these flaws covered essentially 360

Serial No. 07-01 16 Docket No. 50-423 Response to Request for Additional Information Attachment 1 page 3 of 13 degrees circumferentially. The pressurizer spray weld and adjacent weld were overlay repaired and a manual PDI baseline UT of the weld overlay was performed with no reportable indications. Regarding the three safety valve nozzle to safe end welds (weld nos. 03-X-5644-A-T at 81° azimuth, 03-X-5648-B-T at 147O azimuth, and 03-X-5649-C-T 3 at 212O azimuth), and the relief valve nozzle to safe end weld (weld no. 03-X-5650-D-T at 278O azimuth) that are part of this request, essentially 100% coverage for axial indications was performed with a PDI UT. RT was also performed to ensure coverage for circumferential indications due to the as-found field condition weld crown and no reportable indications were identified. The adjacent safe end to pipe welds (weld nos. RCS-516-FW-1, RCS-516-FW-3, RCS-516-FW-5, and RCS-513-FW-1) were not examined. No UT or RT was performed on the surge line nozzle to safe end weld. Profile data was taken only to determine information for future inspectability of these welds.

NRC Question 3 In Section 4.2 of Alternative Request 1R-2-47, the licensee stated that the preemptive weld overlay is designed based on the worst case flaw in the original weld. Describe the size of the worst case flaw (e.g., length, depth, axial or circumferential).

DNC Response In accordance with Enclosure 1, Section 2, Crack Growth and Design, (b)

Structural Design and Sizing, (6) "For mitigative full structural overlays, the assumed flaw in the underlying base material or weld is to be based on the limiting case of the two below:

(a) 100% through wall for the entire circumference, or (b) 100% through wall for 1.5 inches (38 mm) or the combined width of the weld plus buttering, whichever is greater, in the axial direction for the entire circumference.

NRC Question 4 In Section 4.2 of Alternative Request 1R-2-47, the licensee stated that the analysis for the weld overlay design will not be available until April 1, 2007. The licensee requested staff approval of Request IR-2-47 by Spring 2007. The staff requests that the licensee submit the weld overlay design analysis earlier than the requested approval date. The design analysis should include the methodology with relevant ASME Code allowables, the weld overlay thickness, and component dimensions and configurations (e.g., nozzles, welds, safe ends, and piping).

Serial No. 07-01 16 Docket No. 50-423 Response to Request for Additional Information Attachment 1 page 4 of 13 DNC Response April 1, 2007, remains the projected date that WCAP-16734-PI "Millstone 3 Pressurizer Safety, Relief and Surge Nozzles Structural Weld Overlay Qualification," will be complete. DNC is working with its vendor, WestinghouseIPCI, to improve this date.

NRC Question 5 In Section 4.3 of Alternative Request IR-2-47, the licensee stated that it will not perform UT examination on the dissimilar metal welds and similar metal welds prior to weld overlay installation. Without conducting an UT examination of the dissimilar metal welds and similar metal welds prior to weld overlay installation, the condition of the original welds may not be known after the weld overlay installation. This is because of the following concerns. If a flaw existed in the original weld and the weld is not examined prior to weld overlay, the flaw would not be adequately modeled in the crack growth calculation because the initial flaw size would not be known. The flaw may be squeezed tightly by the compressive stresses produced by the weld overlay and may not be able to be detected by the UT after the installation. The UT examination performed after weld overlay installation is qualified to interrogate only the outer 25 percent of the original weld thickness. The condition of the remaining 75 percent of the original weld thickness region would not be known. In light of these concerns, discuss the flaw size that is assumed in the crack growth calculation for the dissimilar and similar metal weld.

DNC Response Per Section 2 (a) of Attachment 2, Enclosure 1, when no UT examination is performed prior to the mitigative weld overlay a postulated 360 degree circumferential flaw 75% though the original wall thickness will be used for the crack growth calculations. Similarly, an axial flaw 75% though the original wall thickness set at 1.5 inches or the combined width of the weld, whichever is greater will also be used for the crack growth calculations. Any actual flaw that exceeds the depth of these assumptions would be detectable by the qualified post weld overlay UT examinations.

NRC Question 6 In Section 5.0 of Alternative Request IR-2-47, the licensee stated that future inservice examinations of weld overlays beyond the current inspection interval will be as required by the NRC in the regulations or as stipulated in the guidance provided under MRP-139. This description is not clear. Describe the exact inservice examination of the weld overlay beyond the current inspection interval.

Serial No. 07-01 16 Docket No. 50-423 Response to Request for Additional Information Attachment 1 page 5 of 13 DNC Response The inservice examinations of weld overlays applied in accordance with Request IR-2-47, Revision 1, will be completed in accordance with the requirements of Section 3 (c) of Attachment 2, Enclosure 1.

Questions on Code Case N-740 in Enclosure 1 to the October 17, 2006 letter NRC Question 7 Paragraph 1 (d) 2 discusses the chromium content and dilution zone. There can be sufficient variations in chemistry within a specific weld group to affect the chemical reproducibility in a field weld. To minimize the effects of chemical dilution and reproducibility between the procedure qualification record (PQR) and of a given weld layer applied in the field, the weld material specification used for the PQR should be the same weld specification used for the weld overlay.

Discuss if this practice will be maintained.

DNC Response The PQRs for qualification of the temperbead portion of the welds and for overlay of the buttered P3 nozzle material were performed using ERNiCrFe-7 (Alloy 52) or ERNiCr Fe-7A (52M) filler metal. Both have 28.0 to 31.5 % Cr, the same as the 52M filler metal that will be used for the production overlays. These are the areas of highest concern for base metal dilution because of the low chromium levels in the low alloy steel. The weld overlay procedure will deposit a sacrificial layer to prevent dilution from the underlying base and weld metals from lowering the Cr content below 24%. This sacrificial layer will be approximately 1132-inch to 1116-inch in thickness and will not be used as part of the weld overlay design thickness. This sacrificial layer will cover the nozzle, the nozzle to safe end weld, the safe end, the safe end to pipe weld, and the pipe as depicted in , Figure 1. Details regarding DNC1s contingency plan for hot cracking that could result from high sulfur content in austenitic stainless steel base material is described in Attachment 2, Section 4.4.

Serial No. 07-0116 Docket No. 50-423 Response to Request for Additional Information Attachment 1 page 6 of 13 NRC Question 8 Paragraph 2 (a) of Code Case N-740 states that flaw characterization and evaluation requirements shall be based on the as-found flaw. However, in Section 4.3 of Alternative Request IR-2-47, the licensee stated that it will not perform an UT examination prior to weld overlay installation, which implies that the information regarding the as-found flaw will not be available. Under this circumstance, discuss how the flaw characterization and evaluation requirements of Paragraph 2 (a) will be satisfied.

DNC Response The crack growth requirements of Paragraph 2 (a) (2) of Attachment 2, will be applied in accordance with Request IR-2-47, Revision 1.

NRC Question 9 Does paragraph 2 (b) (6) apply to the flaws in the weld overlay or only the base metal? If paragraph 2 (b) (6) applies to the weld overlay, any flaws in the weld overlay should be evaluated according to IWX-3500 and the flaw's dimensions should include the UT tolerance associated with the qualification. As is required in paragraph 2 (b) (6), the flaws are evaluated in accordance with IWX-3640 and not IWX-3500. Clarify the intent of paragraph 2 (b) (6).

DNC Response The flaws being evaluated are associated with the underlying base material or existing weld. The requirements of Paragraph 2 (b) (7) of Attachment 2, Enclosure 1 will be applied in accordance with Request IR-2-47, Revision 1, but will not be applied to planar flaws in the weld overlay.

NRC Question 10 Paragraphs g (2) and g (3) of Code Case N-504-2 require evaluations of residual stresses and flaw growth of the repaired weldments. Similar evaluations are required in Section 2 of Code Case N-740. Paragraph 2 (b) 7 of Code Case N-740 states that the effects of any changes in applied loads, as a result of weld shrinkage from the entire overlay on other items in the piping system shall be evaluated. (A) Confirm that the analysis in Paragraph 2 (b) will include results showing that the requirements of Subarticles NB-3200 and NB-3600 of the ASME Code, Section Ill are satisfied. (B) Confirm that the analysis includes the crack growth calculations to demonstrate that crack growth in the weld overlay or base metal is acceptable and residual stress distribution in the weld overlay and original weld demonstrate favorable stress distribution. The staff requests that

Serial No. 07-0116 Docket No. 50-423 Response to Request for Additional Information Attachment 1 page 7 of 13 the licensee submit the preliminary results of the evaluations prior to entry into Mode 4 from the refueling outage and the final evaluations within 60 days of the plant restart.

DNC Response (A)(B) The analysis of the effects of changes in applied loads as a result of weld shrinkage will address the requirements of Subarticles NB-3200 and NB-3600 of the ASME Code Section Ill in accordance with the requirements in Section 2 of and includes the crack growth calculations to demonstrate that crack growth in the weld overlay or base metal is acceptable and residual stress distribution in the weld overlay and original weld demonstrate favorable stress distribution.

DNC will submit the preliminary results of the evaluations prior to entry into Mode 4 from RFO 11 and will submit the final evaluations within 60 days of the plant restart. (Refer to the required activities in Section 4.3.1 of Attachment 2.)

NRC Question 11 Section 3 (a) 2 of the proposed alternative requires that the weld overlay and the adjacent base material for at least one-half inch from each side of the weld shall be examined using the liquid penetrant method. This requirement is not consistent with Section 4.0 (b) of Code Case N-638-1, which requires surface and ultrasonic examination of a band on either side of the overlay with an axial length of at least 1.5 times the component thickness or 5 inches whichever is greater. Discuss why the proposed requirement is sufficient.

DNC Response Since N-638-1 was written as a viable alternative for construction requirements associated with temper bead welding for cavity repairs, many of the requirements in the Code Case were drawn directly from Section Ill. ASME committees responsible for Code Case N-740 determined there is no real basis to consider base metal cracking would exist beyond the normal butt weld surface examination requirements of 112 inch when applying a weld overlay. Therefore, alternative requirements in N-740 and DNC's alternative in Attachment 2, Enclosure 1 reflect these criteria. Since the welding is on the surface of the base metal and associated welds, the heat-affected zone beyond the edges of the overlay is sufficiently covered by the 112 inch requirement.

Serial No. 07-01 16 Docket No. 50-423 Response to Request for Additional Information Attachment 1 page 8 of 13 NRC Question 12 (A) Based on Paragraph 3 (b) 2, if a flaw is detected in the outer 25 percent of the base metal (or original weld) during the preservice examination, the observed flaw size would be used for the crack growth evaluation. The staff does not believe this is a conservative assumption for the crack growth calculation if the original weld was not examined prior to weld overlay. The current ultrasonic examination is qualified only to detect flaws in the outer 25 percent of the pipe base metal after a weld overlay is applied. Therefore, the condition in the inner 75 percent of the pipe base metal would not be known. A conservative assumption would be to assume existence of a crack of 75 percent throughwall depth in the inner 75 percent pipe base metal which should be added to the depth of the crack found in the outer 25 percent of the pipe base metal. This worst case crack should be used to calculate crack growth. Discuss why it is acceptable to assume the observed flaw size for the crack growth calculation when the ultrasonic examination is only qualified for the outer 25 percent of the pipe metal.

DNC Response The applicable requirements of Code Case N-740, Paragraph 3 (b) (2) have been expanded and are included as 3 (b) (3) in Enclosure 1 to address this issue. The paragraph reads, "The flaw evaluation requirements of IWB-3640, IWC-3640 or, IWD-3640 shall not be applied to indications identified during preservice examination, which exceed the preservice examination standards of Table IWB-3514-2." The design thickness of the weld overlay is based on a 100% through wall flaw. DNC understands the limitation of the UT examination described in the question. If flaws are found in the outer 25 percent of the existing base metal or weld and can not be determined to be isolated from the ID of the existing base material or weld, the flaw depth will be conservatively sized by adding the thickness of the remaining 75 percent of the original existing base metal or weld thickness to the through wall dimension for any flaw growth calculations performed. Isolated flaws that do not encroach on the interface between the outer 25 percent of the original base metal or weld thickness and the inner 75 percent of the same existing materials and that can be determined by the qualification parameters of the UT examination to not be connected to the interface of the outer 25 percent with the inner 75 percent, will be evaluated based on their actual UT-determined through wall dimension for any crack growth analysis performed.

NRC Question 13 (A) Paragraph 3 (c) 3 requires that "...The inservice examination acceptance standards of Table IWB-3514-2 shall be met for the weld overlay. Alternatively,

Serial No. 07-01 16 Docket No. 50-423 Response to Request for Additional Information Attachment 1 page 9 of 13 for Class 1, 2, or 3 piping systems, the acceptance criteria of IWB-3640, IWC-3640, as applicable, shall be met for weld overlay...". Weld overlays are designed to mitigate a specific crack growth mechanism in the base metal. The construction flaws are considered benign. If flaw growth occurs in the weld overlay, the initial assumptions for the weld overlay and construction flaws may not be correct and the mechanisms causing degradation in the weld overlay may not be thoroughly understood. Any crack growth in a weld overlay should be investigated to determine its root cause. The staff would accept the acceptance criteria of IWB-3600 for the flaw in the weld overlay if the flaw growth is caused by thermal fatigue which would be insignificant. However, flaw growth by primary water stress corrosion cracking could be significant and the staff would find such growth mechanism unacceptable. Justify the acceptance criteria of IWB-3600 for the primary water stress corrosion cracking in the weld overlay per paragraph 3 (c) 3.

DNC Response , Enclosure 1 specifies flaw growth evaluation requirements in Paragraph 3 (c) (4). DNC recognizes it could be difficult to determine whether flaw growth into a weld overlay is either from fatigue or existing PWSCC.

However, based on industry experience, it is not expected that flaw growth into the weld overlay material will occur. If flaw growth in the weld overlay does occur, and the acceptance Standards of IWB-3514-2 cannot be met, or a determination cannot be made to prove that it is not PWSCC, DNC will repair the flaw and will not use IWB-3600, IWC-3600, or IWD-3600 to accept these types of flaws. (Refer to the required activities in Section 4.3.1 of Attachment 2.)

Questions on Mandatory Appendix 1 to Code Case N-740 NRC Question 14 Paragraph 1.0 (a) of Code Case N-638-1 limits the thickness of the weld overlay not to exceed the 50 percent of the ferritic base metal thickness. Discuss why this requirement is not included in Section 1.0 of Appendix 1 to Code Case N-740.

DNC Response As stated in the response to NRC Question 11, N-638-1 was written as a viable alternative for Construction requirements associated with temper bead welding for cavity repairs. Weld depth is not a parameter associated with temper bead welding of a weld overlay, therefore, it was not considered an applicable requirement and was not included in the Code Case and is not included in Enclosure 1.

Serial No. 07-01 16 Docket No. 50-423 Response to Request for Additional Information Attachment 1 page 10 of 13 NRC Question 15 Paragraph 1 (b) of Appendix 1 to Code Case N-740 states that the maximum area of the weld overlay based on the finished surface over the ferritic base material shall be 500 square inches. Code Case N-638-1 allows only I 0 0 square inches. The licensee needs to provide justification for the 500 square inch surface area.

DNC Response The ASME has indicated that the ID compressive stress levels remain essentially the same between 100 square inches and 500 square inches in relation to weld overlay applications. Therefore, this change was added to the Code Case N-740 and is included in Attachment 2, Enclosure 1. The justification entitled, "Bases for 500 Sq. In. Weld Overlay Over Ferritic Material," was provided to the NRC staff in the January 10, 2007 meeting (ADAMS Accession No. ML070470565).

Additional justification is provided in EPRl Report 1014351, "Repair and Replacement Applications Center: Topical Report Supporting Expedited NRC Review of Code Cases for Dissimilar Metal Weld Overlay Repairs, December 2006."

NRC Question 16 Section 2 (g) of Appendix 1 to Code Case N-740 provides additional requirements for the case when the average lateral expansion value of the heat affected zone of Charpy V-notch specimens is less than the average value for the unaffected base metal. This requirement is not shown in Code Case N-638-1. Discuss the technical basis for the requirements in Section 2 (g) of Appendix 1.

DNC Response Alternative Request IR-2-47, Revision 1, Enclosure 1 does not include the provisions of Code Case N-740, Appendix 1, Paragraph 2 (g). The average lateral expansion value requirements for the heat affected zone (HAZ) Charpy V-notch specimens are being met with no additional alternatives being applied.

NRC Question 17 Section 3.0 (c) of Appendix 1 to Code Case N-740 states that the heat input of the first three layers shall not exceed 45,000 Jlinch under any conditions.

Provide the technical basis for this requirement which is not shown in Code Case N-638-1.

Serial No. 07-01 16 Docket No. 50-423 Response to Request for Additional Information Attachment 1 page 11 of 13 DNC Response , Enclosure 1, Appendix 1, Section 3 (c) is the same as in Code Case N-740. This heat input limit is conservative and was made a requirement by the responsible ASME committees to provide the best combination of mechanical properties that can be expected when performing temper bead welding. Later ASME approved revisions to Code Case N-638-1 include this provision.

NRC Question 18 Section 3.0 (c) of Code Case N-638-1 requires that for similar metal welding, the completed weld shall have at least one layer of weld reinforcement deposited.

This reinforcement shall be removed by mechanical means, so that the finished surface is flush with the surface surrounding the weld. Discuss why this requirement is not included in Section 3.0 (c) of Appendix 1 to Code Case N-740 because the licensee will weld overlay similar metal welds as well as dissimilar metal welds.

DNC Response This requirement in Code case N-638-1 was written for application of ferritic weld material and is not necessary for austenitic material as no tempering occurs in this material. Therefore, the requirement was not included in Code Case N-740 or the alternative requirements of Enclosure 1 of Attachment 2.

NRC Question 19 Section 3.0 (d) of Appendix 1 to Code Case N-740 states that the interpass temperature limitation of QW-406.3 does not need to be applied. This condition is not included in Code Case N-638-1. Discuss why this condition is included in Appendix 1.

DNC Response ASME committees responsible for the development of Code Case N-638-2 and N-740 determined that this was an unnecessary requirement. Therefore, it was not included in N-740 because the more restrictive heat limits placed on temper bead weld parameters would control the metallurgical and physical properties with the application of temper bead welding.

Serial No. 07-0116 Docket No. 50-423 Response to Request for Additional Information Attachment 1 page 12 of 13 NRC Question 20 Paragraph 3 (e) of Appendix 1 to Code Case N-740 has been incorporated in Code Case N-638-2, but not in N-638-1. The staff has not approved Code Case N-638-2 and does not agree with Paragraph 3 (e) of Appendix 1. The staff's position is that the licensee should use the temperature measurements (e.g.,

pyrometers, temperature indicating crayons, and thermocouples) of Paragraph 3 (e) 1. When it is impractical to use interpass temperature measurement methods described in this paragraph due to situations where the weldment area is inaccessible, such as internal bore welding, or when there are extenuating radiological conditions, either paragraph 3 (e) 2 or paragraph 3 (e) 3 may be used. The licensee needs to revise the proposed Paragraph 3 (e).

DNC Response As part of the Westinghouse /PC1 weld process, DNC will use contact pyrometers to determine interpass temperatures based on ALARA concerns, as allowed by Appendix 1, Paragraph 3 (e) (1) of Enclosure 1 of Attachment 2.

NRC Question 21 Section 4.0 (c) of Code Case N-638-1 requires that areas from which weld-attached thermocouples have been removed be ground and examined using a surface examination method. Discuss whether this requirement should be included in Appendix 1 and provide a justification for your response.

DNC Response , Enclosure 1, Appendix 1 Paragraph 3 (e) does not provide information regarding examination of areas where weld-attached thermocouples are removed. DNC does not plan to use weld-attached thermocouples during the weld overlay applications at MPS3. If weld-attached thermocouples are used, the areas where the thermocouples are removed will be ground and examined using a surface examination method and Construction Code acceptance criteria for the base material.

NRC Question 22 In Regulatory Guide 1.147, Revision 14, the staff imposed a condition on Code Case N-638-1 regarding ultrasonic examination and associated acceptance criteria based on NB-5330 of the ASME Code, Section Ill. Discuss whether this condition will be satisfied.

Serial No. 07-0116 Docket No. 50-423 Response to Request for Additional Information Attachment 1 page 13 of 13 DNC Response Ultrasonic examination requirements for the weld overlays are provided in Section 3 of Attachment 2, Enclosure 1, which specifies UT is to be performed in accordance with Section XI. Unlike ASME Section Ill requirements, the ASME Section XI UT examination is qualified based on performance demonstration for both personnel and procedures, and it has been proven to be capable for this application by that process. Therefore, in this application, UT in accordance with ASME Section XI requirements would be more appropriate than UT using ASME Section Ill requirements. Surface examination requirements of NB-5300 for the weld overlay and NB-2500 for the base material are required for this application.

NRC Question 23 If the pressurizer surge line in MPS3 has been approved for leak-before-break and the weld overlay is applied to the surge line, confirm that the original leak-before-break analyses are still valid and the associated acceptance criteria (e.g.,

the safety margin on crack size and leak rates as specified in Standard Review Plan 3.6.3) are still acceptable.

DNC Response The MPS3 pressurizer surge line nozzle to safe end and safe end to pipe welds are not included as part of the approved leak-before-break analysis.

NRC Question 24 Please commit to provide the NRC, within 14 days after the completion of the ultrasonic examination of the weld overlay installations, (1) the examination results of the weld overlays, and (2) a discussion of any repairs to the overlay material and/or base metal and the reason for the repair.

DNC Response DNC will provide: (1) the examination results of the weld overlays, and (2) a discussion of any repairs to the overlay material andlor base material and the reason for the repair within 14 days after the completion of the ultrasonic examination of weld overlay installations. (Refer to the required activities in Section 4.3.1 of Attachment 2.)

Serial No. 07-01 16 Docket No. 50-423 ATTACHMENT 2 ALTERNATIVE REQUEST IR-2-47, REVISION 1 USE OF WELD OVERLAYS AS AN ALTERNATIVE REPAIR TECHNIQUE DOMINION NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION UNIT 3

Serial No. 07-01 16 Docket No. 50-423 Alternative Request IR-2-47, Revision 1 Attachment 2 Page 1 of 9 ALTERNATIVE REQUEST IR-2-47, REVISION 1 USE OF WELD OVERLAYS AS AN ALTERNATIVE REPAIR TECHNIQUE CONTENTS 1.0 REASON FOR THE REQUEST ................................................................... . 2 2.0 CODE COMPONENTS FOR WHICH THE ALTERNATIVE IS REQUESTED ................................................................................................. 2 3.0 CODE REQUIREMENTS FOR WHICH THE ALTERNATIVE IS REQUESTED ................................................................................................ 3 4.0 PROPOSED ALTERNATIVES AND SUPPORTING INFORMATION ............ 4 5.0 DURATION OF THE PROPOSED REQUEST ............................................... 8 6.0 PRECEDENTS .............. . ................................................................................ 8

7.0 REFERENCES

............................................................................................... 8

8.0 CONCLUSION

................................................................................................ 9 FIGURES Figure 1 -Typical Weld Overlay Repair Configuration .................................... 5 ENCLOSURE 1 Alternative Requirements for Dissimilar Metal Weld Overlays ........................ 13 pages

Serial No. 07-01 16 Docket No. 50-423 Alternative Request IR-2-47, Revision 1 Attachment 2 Page 2 of 9 ALTERNATIVE REQUEST IR-2-47, REVISION 1 USE OF WELD OVERLAYS AS AN ALTERNATIVE REPAIR TECHNIQUE Proposed Alternative In Accordance with 10 CFR 50.55a(a)(3)(i)

- Alternative Provides Acceptable Level Of Quality And Safety -

1.0 REASON FOR THE REQUEST For the upcoming cycle 11 refueling outage ( 3 R l l ) , five high safety significant (HSS) dissimilar metal welds located on the pressurizer are currently scheduled to have full structural preemptive weld overlays (PWOLs) applied at Millstone Power Station Unit 3 (MPS3). Repairlreplacement activities associated with PWOL repairs are required to address the materials, welding parameters, ALARA concerns, operational constraints, examination techniques and procedure requirements for repairs. Comprehensive and generic NRC approved criteria are, however, not currently available for application of PWOL repairs to dissimilar metal welds constructed of Alloy 821182 weld material for mitigation of potential primary water stress corrosion cracking (PWSCC).

2.0 CODE COMPONENTS FOR WHICH THE ALTERNATIVE IS REQUESTED Code components associated with this request are the high safety significant (HSS)

Class 1 dissimilar metal piping welds with Alloy 821182 weld metal that are believed to be susceptible to PWSCC. The components are also scheduled for examination in accordance with the risk-informed inservice inspection (RI-ISI) and the guidelines of MRP-139 (Reference 3). There are five welds that are scheduled to have full structural PWOLs applied. The additional examination requirements of the RI-IS1 program and MRP-139 will be met with application of these five PWOLs.

2.1 Category and System Details Code Class: All listed welds are ASME Code Class 1 welds.

System Welds: Components are located in the Reactor Coolant System (RCS) pressure boundary.

Code Category: Examination Category R-A, "Risk-Informed Piping Examinations" Code Item No.: R1.15, "Elements Subject to PWSCC"

Serial No. 07-01 16 Docket No. 50-423 Alternative Request IR-2-47, Revision 1 Attachment 2 Page 3 of 9 2.2 Component Descriptions The application of this alternative for the five potentially susceptible nozzle-to-safe end welds using PWOL includes the weld overlay of the adjacent stainless steel safe end-to-pipe welds any time a PWOL is applied.

I . Weld No. 03-X-5551-X-T: 14-inch RCS Safe End-To-Surge Nozzle and adjacent Safe End-To-Pipe (Weld No. RCS-SL-FW-4),

2. Weld No. 03-X-5644-A-T: 6-inch Safety Nozzle-To-Safe End Weld at 81° Azimuth and adjacent Safe End-To-Pipe (Weld No. RCS-516-FW-I),

3. Weld No. 03-X-5648-B-T: 6-inch Safety Nozzle-To-Safe End Weld at 147O Azimuth and adjacent Safe End-To-Pipe (Weld No. RCS-516-FW-3),

4. Weld No. 03-X-5649-C-T: 6-inch Safety Nozzle-To-Safe End Weld at 212' Azimuth and adjacent Safe End-To-Pipe (Weld No. RCS-516-FW-5), and

5. Weld No. 03-X-5650-D-T: 6-inch Relief Nozzle-To-Safe End Weld at 278' Azimuth and adjacent Safe End-To-Pipe (Weld No. RCS-513-FW-I).

2.3 Component Materials

1. All Nozzles are (P-3) Alloy Steel, SA-508 CL2,

2. Nozzle-To-Safe End Weld and Butter are Alloy 821182 (F-43),

3. Safe Ends are (P-8) Wrought Stainless Steel (SS), SA-182 GR F316C, and

4. Surge Line, Safety Line, and Relief Line Pipes, are (P-8) Wrought SS.

3.0 CODE REQUIREMENTS FOR WHICH THE ALTERNATIVE IS REQUESTED MPS3 is currently in the second 10-year IS1 interval that began on April 23, 1999, and is scheduled to end October 23, 2008. The ASME Boiler and Pressure Vessel Code (ASME Code) of record for the current 10-year IS1 interval and the RI-IS1 program is the 1989 Edition of Section XI of the ASME Code.

The ASME Code,Section XI, 1998 Edition, no Addenda, IWA-4000 (Reference I ) ,

is used for the MPS3 Section XI repairlreplacement program,(2)which does not have the needed requirements for this type of repair. The ASME Code requirements for which the relief is requested are contained in the following:

Serial No. 07-0116 Docket No. 50-423 Alternative Request IR-2-47, Revision 1 Attachment 2 Page 4 of 9

1. 1998 Edition with no Addenda of the American Society of Mechanical Engineers (ASME) Code,Section XI, IWA-4000, (Reference 1).

2. 1995 Edition with the I996 Addenda, of the ASME Code,Section XI, Appendix VIII, Supplement 11, (Reference 5).

The alternative described in Section 4.0 is proposed to permit the implementation of scheduled PWOLs at MPS3, as an alternative for the repairlreplacement requirements of the ASME Code,Section XI, 1998 Edition with no Addenda, IWA-4000 (Reference 1).

The ultrasonic examination of the completed structural weld overlay will be accomplished in accordance with the ASME Code,Section XI, 1995 Edition with the I996 Addenda, Appendix VIII, Supplement 11 (Reference 5). These examinations will be in accordance with the requirements of 10 CFR 50.55a(g)(6)(ii)(C), that apply to implementing Appendix VIII, with the alternatives used for complying with the Performance Demonstration Initiative (PDI) program that are documented for MPS3 in NRC approval of Relief Request IR-2-39, dated January 20, 2006 (ADAMS Accession No. ML053260012).

4.0 PROPOSED ALTERNATIVES AND SUPPORTING INFORMATION Dominion Nuclear Connecticut, Inc. (DNC) is proposing to use alternative requirements submitted for NRC staff review in Enclosure 1 for use under the provisions of 10 CFR 50.55a(a)(3)(i). These alternative requirements are the result of the industry's experience with weld overlay repairs for flaws suspected or confirmed to be from PWSCC, and for the first time provide guidance which is being directly applied to the Alloy 521152 weld material that is used for these overlay repairs.

This proposal requests the use of the alternative requirements for implementing the five scheduled full structural PWOLs for the potentially PWSCC susceptible nozzle-to-safe end welds of the pressurizer. These PWOLs will include the adjacent stainless steel safe-end-to-pipe welds. This request applies to each of the welds listed in Section 2.2, which are generically depicted in Figure 1 of this section.

Serial No. 07-01 16 Docket No. 50-423 Alternative Request IR-2-47, Revision 1 Attachment 2 Page 5 of 9 7 Safe End (SS)

NozzlelSE Weld 1

Ferritic Steel Nozzle /

I Figure 1 -Typical Weld Overlay Repair Configuration A full structural PWOL (designed for the worst case flaw) will be applied in accordance with the alternative requirements in Enclosure 1 with a UT examination following the application of the PWOL.

4.1 The Structural Weld Overlay Assembly The ferritic material of the nozzles is (P3), the safe ends and pipes are wrought stainless steel (P8) material. The existing weld filler material is Alloy 821182 (F43 equivalent to P43).

The full structural weld overlay satisfies all the structural design requirements of the pipe assuming no strength contributed by the pipe, as if the pipe were not there. As shown in Figure 1 of this section, this structural weld overlay (weld reinforcement) will completely cover the existing Alloy 821182 weld metal and will extend onto the ferritic and austenitic stainless steel material on each end of the weld, including the adjacent safe end-to-pipe weld. Although the weld overlay extends the full 360" around the nozzle, a cross section depicting only half is shown in Figure 1 for clarity.

4.2 Weld Overlay Design The PWOLs will be designed as full structural overlays (assumed worst case flaw) in accordance with section 2.0 of the alternative requirements of Enclosure 1. The details surrounding the design analysis for the PWOLs are being developed to support the MPS3 spring 2007 refueling outage and DNC's vendor has committed to supplying this analysis to DNC by April 1, 2007. As soon as this analysis is available it will be submitted for NRC review, but no later than prior to entry into Mode 4 in the startup from 3R11. (Reference DNC commitment from letter dated October 17, 2006.)

Serial No. 07-01 16 Docket No. 50-423 Alternative Request IR-2-47, Revision 1 Attachment 2 Page 6 of 9 4.3 Examinations All examinations will meet requirements of the alternative requirements of Enclosure 1, excluding a UT examination after a completed PWOL. The UT examination after a completed PWOL will be performed in accordance with ASME Code Section XI, 1995 Edition with the 1996 Addenda, Appendix VIII, Supplement 11 (Reference 5) with the alternatives that are used to comply with the Performance Demonstration Initiative (PDI) program, as described in the NRC review and approval of MPS3 request IR-2-39, dated January 20, 2006 (ADAMS Accession No. ML053260012).

The current configuration of these welds does not permit an ASME Code Section XI, Appendix VIII, Supplement 10 (Reference 4), UT weld examination without extensive machining. Therefore, none of these welds will receive a pre-weld overlay UT examination. However, if the welds are found with PWSCC or other unacceptable flaws during the post weld overlay UT examination, no additional weld examinations of other similar welds will be performed because there will be no remaining similar trimetallic welds that are associated with the pressurizer environment that will not have been overlay repaired during this activity.

4.3.1 Required Activities DNC will submit the preliminary results of the evaluations of the effects of changes in applied loads as a result of weld shrinkage prior to entry into Mode 4 from RFO 11 and will submit the final evaluations within 60 days of the plant restart. (Refer to the response to RAI Question 10 in Attachment 1.)

If flaw growth in the weld overlay does occur and the acceptance Standards of Table IWB-3514-2 cannot be met, or a determination cannot be made to prove that it is not PWSCC, DNC will repair the flaw and will not use IWB-3600, IWC-3600, or IWD-3600 to accept these types of flaws. (Refer to the response to RAI Question 13 in Attachment 1.)

DNC will provide: (1) the examination results of the weld overlays, and (2) a discussion of any repairs to the overlay material and/or base material and the reason for the repair within 14 days after the completion of the ultrasonic examination of weld overlay installations. (Refer to the response to RAI Question 24 in Attachment 1.)

Serial No. 07-0116 Docket No. 50-423 Alternative Request IR-2-47, Revision 1 Attachment 2 Page 7 of 9 4.4 Contingency for Hot Cracking Operating experience exists for hot cracking in the first layer of nickel alloy weld overlay (WOL) deposits over stainless steel base materials. The major WOL vendors are currently conducting extensive investigations into this phenomenon.

Initial results have shown that higher levels of sulfur in the austenitic stainless steel base metal substrate can cause this hot cracking.

DNC and DNC's vendor, PCI, both believe that the possibility of this hot cracking occurring in the MPS3 pressurizer nozzle PWOLs is remote based on the following:

1. Previous application of a WOL on the MPS3 pressurizer spray nozzle conducted in 3R10 (October of 2005) showed no evidence of hot cracking.

2. Certified material test reports (CMTRs) for all of the stainless steel materials involved in this request have lower sulfur content than the spray nozzle that had a weld overlay applied in 2005 and had a sulfur content of 0.015. The CMTRs also have lower sulfur content than the stainless steel material in which hot cracking has been found, either in production welds or in mock-up welds including those designed specifically to induce hot cracking.

In light of the above, no special operations are recommended for prevention of hot cracking at MPS3. However, because the investigation of this phenomenon is still ongoing and the exact levels of sulfur and other elements or combinations of elements required to preclude hot cracking are unknown, DNC will implement the following contingency:

The nozzle safe end weld with the highest sulfur content will be one of the first welds to have PWOL performed. An informational liquid penetrant (LP) examination will be performed on the relevant portion (stainless steel safe end) of the first layer of the PWOL. If indications of hot cracking are identified, as determined by the welding engineer, the suspect nickel alloy weld metal will be completely removed along with any indications in the underlying base metal of the stainless steel safe end. Complete removal of the nickel alloy weld metal shall be verified by acid etch and the resulting cavity shall be LP inspected.

Then weld build-up will be applied to the cavity using stainless steel weld material for the bulk of the build-up with the final tie-in to the existing nickel alloy weld being performed using nickel alloy weld metal. This weld build-up will serve two purposes:

1. Restore the stainless steel base metal to its original contour.

2. Provide an improved base layer for application of the PWOL that will reduce the susceptibility to hot cracking.

Serial No. 07-01 16 Docket No. 50-423 Alternative Request IR-2-47, Revision 1 Attachment 2 Page 8 of 9 This application of weld build-up is not part of the PWOL and will be performed in accordance with the requirements of MPS3 Section XI RepairIReplacement program, and ASME Section Ill, which meets the requirements of the ASME Code Section XI, I998 edition with no addenda, IWA-4000.

5.0 DURATION OF THE PROPOSED REQUEST The alternative requirements of this request for the application of PWOLs will be applied for the duration of, up to and including, the last outage of the current, second 10-year IS1 interval. Inservice examination requirements for PWOLs will be applied in accordance with the alternative requirements of Enclosure 1, Section 3 (c). The inservice examination requirements are also applicable to the weld overlay previously applied to the pressurizer spray nozzle to safe end dissimilar metal weld (Weld No. 03-X-5641-E-T).

PRECEDENTS The only other PWSCC susceptible weld located within the pressurizer environment at MPS3 is the spray nozzle-to-safe end weld (Weld No. 03-X-5641-E-T) that was weld overlay repaired in 3R10 under NRC approved relief request IR-2-39 (ADAMS Accession No. ML053260012) along with its adjacent safe end-to-pipe weld (Weld No. RCS-517-FW-12). Both of these welds, which are now weld overlay repaired, will receive their first inservice UT examination during the upcoming 3R11 refueling outage.

Similar requests have been submitted to address the issues that are contained in this request. These include requests from the lndiana Michigan Power Company's, D. C. Cook Unit 2. NRC verbal approval was received on March 23, 2006, for the D.C. Cook request, which included the application of full structural PWOLs applied to the Unit 2 pressurizer steam space dissimilar metal butt welds. Additionally, the following requests associated with WOL repairs have been approved by the NRC:

AmerGen Energy Company's Three Mile Island Nuclear Station Unit 1 on July 21, 2004,'~)Constellation Energy's Calvert Cliffs Nuclear Power Plant Unit 2 on July 20, 2005,'~)DNC1sMillstone Unit 3 on January 20, 2006,'~)and lndiana Michigan Power Company's Donald C. Cook Unit 1 on February 10, 2006.@)

7.0 REFERENCES

1. ASME Code,Section XI, 1998 Edition, no Addenda, IWA-4000.

2. ASME Code Case N-740, Dissimilar Metal Weld Overlay for Repair of Class 1, 2, and 3 Items,Section XI, Division 1, July 14, 2006.

Serial No. 07-01 16 Docket No. 50-423 Alternative Request IR-2-47, Revision 1 Attachment 2 Page 9 of 9

3. Material Reliability Program: Primary System Piping Butt Weld lnspection and Evaluation ~ u i d e l i n e (MRP-139), EPRI, Palo Alto, CA: 2005.

1010087.

4. ASME Code,Section XI, 1995 Edition with the 1996 Addenda, Appendix VIII, Supplement 10.

5. ASME Code,Section XI, 1995 Edition with the 1996 Addenda, Appendix VIII, Supplement 11.

8.0 CONCLUSION

Similar NRC approved requests have been used to produce acceptable weld overlays when applied to dissimilar metal welds with Alloy 821182 weld material.

The proposed alternative requirements in Enclosure 1 were developed to cover the most recent operating experience and NRC approved criteria that are associated with similar PWOL applications. Therefore, DNC considers that these alternative requirements provide an acceptable level of quality and safety, consistent with provisions of 10 CFR 50.55a(a)(3)(i).

NRC letter, "Safety Evaluation of Relief Request For A Risk-Informed lnservice lnspection Program, Millstone Power Station, Unit No. 3 (TAC No. MA9740)," dated March 12, 2002, (ADAMS Accession No. ML020570312).

NRC letter, "Millstone Power Station, Unit Nos. 2 and 3 RE: Request to Use 1998 Edition, with No Addenda, of ASME Section XI for RepairIReplacement Activities (TAC Nos. MC7347 and MC7348),11 dated September 13, 2005, (ADAMS No. MLO522lOO33).

NRC letter, "Safety Evaluation of Request For Relief From Flaw Removal, Heat Treatment and Nondestructive Examination (NDE) Requirements For The Third 10-Year lnservice lnspection Interval, Three Mile Island Nuclear Station, Unit 1 (TMI-I),

(TAC No. MC1201), dated: July 21, 2004, (ADAMS Accession No. ML041670510).

NRC Letter, "Safety Evaluation for Calvert Cliffs Nuclear Power Plant, Unit No. 2, Relief Request for Use Weld Overlay and Associated Alternative lnspection Techniques (TAC Nos. MC6219 and MC6220), dated July 20, 2005, (ADAMS Accession No. ML051930316).

NRC letter, "Safety Evaluation of Relief Request IR-2-39 Pertaining to the Repair and lnspection of Nozzle to Safe End Weld, Weld No. 03-X-5641-E-T at Millstone Power Station Unit No. 3 (MPS3)," (TAC No. MC8609), dated January 20, 2006, (ADAMS Accession No. ML053260012).

NRC letter, Safety Evaluation of Alternative Request Regarding Repair of Safe-End-To-Elbow Weld 1-RC-9-01F at the Donald C. Cook Nuclear Plant Unit 1, (TAC No.

MC8807), dated February 10, 2006, (ADAMS Accession No. ML060240355).

Serial No. 07-0116 Docket No. 50-423 ENCLOSURE I ALTERNATIVE REQUIREMENTS FOR DISSIMILAR METAL WELD OVERLAYS DOMINION NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION UNIT 3

Serial No. 07-01 16 Docket No. 50-423 Alternative Requirements Enclosure 1 Page Iof 13 ALTERNATIVE REQUIREMENTS FOR DISSIMILAR METAL WELD OVERLAYS In lieu of the requirements of IWA-4410 and IWA-4611, a defect in austenitic stainless steel or austenitic nickel alloy piping, components, or associated welds may be reduced to a flaw of acceptable size in accordance with IWB-3640 by addition of a repair weld overlay.

Alternatively, if mitigation is performed, the weld overlay will be designed by assuming a worst case postulated flaw in accordance with IWB-3640. All Section XI references are to the 2004 Edition with the 2006 Addenda. For the use of these alternative requirements with other Editions and Addenda, refer to Table 1. The weld overlay shall be applied by deposition of weld reinforcement (weld overlay) on the outside surface of the piping, component, or associated weld, including ferritic materials when necessary, provided the following requirements are met.

1 GENERAL REQUIREMENTS A full-structural weld overlay shall be applied by deposition of weld reinforcement (weld overlay) on the outside surface of the low alloy steel nozzles (P-No. 3) to the safe end (P-No. 8 or 43), inclusive of the NO6082 or W86182 weld that joins the two items. The design of the overlay may be extended to include the adjacent stainless steel-to-stainless steel welds (P-No. 8 to P-No. 8).

These alternative requirements apply to dissimilar metal welds between P-No.8 or 43 and P-No.1, 3, 12A, 12B, or 1 2 ~ ' ' )materials. These requirements also apply to dissimilar metal welds between P-No. 8 and P-No.43 materials joined with austenitic F-No.43 filler metal, and to welds between P-No. 8 and P-No. 8 materials as described in paragraph 1 (a) above.

Weld overlay filler metal shall be austenitic nickel alloy (28% Cr min., ERNiCrFe-7 or ERNiCrFe-7A) applied 360 deg. around the circumference of the item, and shall be deposited using a Welding Procedure Specification (WPS) for groove welding, qualified in accordance with the Construction Code and Owner's requirements and identified in the RepairIReplacement Plan. As an alternative to the post weld heat treatment (PWHT) requirements of the Construction Code and Owner's requirements the following provisions may be applied:

(I) INTENTIONALLY DELETED.

(2) Appendix 1 may be used for ambient-temperature temper bead welding.

Prior to deposition of the weld overlay, the surface to be weld overlaid shall be examined by the liquid penetrant method. Indications larger than 1/16 in. (1.5 mm) shall be removed, reduced in size, or corrected in accordance with the following requirements:

(1) One or more layers of weld metal shall be applied to seal unacceptable indications in the area to be repaired with or without excavation. The thickness of these layers shall not be used in meeting weld reinforcement design thickness requirements.

Peening the unacceptable indication prior to welding is permitted.

(2) If repair of indications identified in I(d) is required, the area where the weld overlay is to be deposited, including any local repairs or initial weld overlay layer, shall be examined by the liquid penetrant method. The area shall contain no indications

(') P-Nos. 12A, 12B, and 12C designations refer to specific material classifications originally identified in Section 111 and subsequently reclassified in a later Edition of Section 1X.

Serial No. 07-01 16 Docket No. 50-423 Alternative Requirements Enclosure 1 Page 2 of 13 greater than 1/16 in. (1.5 mm) prior to the application of the structural layers of the weld overlay.

(e) Weld overlay deposits shall meet the following requirements. The austenitic nickel alloy weld overlay shall consist of at least two weld layers deposited from a filler material with a Cr content of at least 28%. The first layer of weld metal deposited may not be credited toward the required thickness. Alternatively, for PWR applications, a diluted first layer may be credited toward the required thickness, provided the portion of the layer over the austenitic base material, austenitic filler material weld and the associated dilution zone from an adjacent ferritic base material contains at least 24% Cr and the Cr content of the deposited weld metal is determined by chemical analysis of the production weld or of a representative coupon taken from a mockup prepared in accordance with the WPS for the production weld. Alternatively, for BWR applications, a diluted first layer may be credited toward the required thickness, provided the portion of the layer over the austenitic base material, austenitic filler material weld and the associated dilution zone from an adjacent ferritic base material contains at least 20% Cr and the Cr content of the deposited weld metal is determined by chemical analysis of the production weld or of a representative coupon taken from a mockup prepared in accordance with the WPS for the production weld.

(f) These alternative requirements are only for welding in applications predicted not to have exceeded thermal neutron fluence of 1 x 1017 (E< 0.5 eV) neutrons per cm2 prior to welding.

(g) A new weld overlay shall not be installed over the top of an existing weld overlay that has been in service.

2 CRACK GROWTH AND DESIGN (a) Crack Growth The size of all flaws detected or postulated in the original weldment shall be projected to the end of the expected life of the overlay. Crack growth due to both stress corrosion and fatigue shall be evaluated. Flaw characterization and evaluation shall be based on the ultrasonic examination results.

(7) For repair overlays, the initial flaw size for crack growth shall be based on the as-found flaw.

(2) For mitigative overlays, the initial postulated flaw size for crack growth shall be assumed consistent with the examinations performed, either pre or post overlay. The axial flaw length shall be set at 1.5 inches (38 mm) or the combined width of the weld plus buttering, whichever is greater. The circumferential flaw length shall be assumed to be 360 degrees.

(a) If an examination is performed prior to application of the overlay, which is qualified in accordance with Appendix VIII, Supplement 11 and no inside surface connected planar flaws are discovered, initial flaws (originated from the inside surface of the weldment) equal to 10% of the original wall thickness shall be assumed in both the axial and circumferential directions.

(b) If no examination is performed prior to application of the overlay, initial flaws equal to at least 75% through the original wall thickness shall be assumed, in both the axial and circumferential directions, consistent with the overlay inservice inspection volume in Fig. 2.

Serial No. 07-01 16 Docket No. 50-423 Alternative Requirements Enclosure 1 Page 3 of 13 (c) There may be circumstances in which an overlay examination is performed using an ultrasonic examination procedure, which is qualified in accordance with Appendix VIII, Supplement 11 for depths greater than the outer 25% of the original wall thickness (Fig. 2). For such cases, initial flaw sizes may be assumed consistent with the depth to which the examination procedure is qualified.

(d) Any inside surface connected planar flaw found by the overlay preservice inspection of paragraph 3(b), which exceed the depth of (a), (b) or (c) above, shall be used as the initial flaw depth in determining the expected life of the overlay. Overlays meeting this condition shall be considered a repair.

(b) Structural Design and Sizing of the Overlay The design of the weld overlay shall satisfy the following, using the assumptions and flaw characterization restrictions in 2(a). The following design analysis shall be completed in accordance with IWA-4311:

( I ) The axial length and end slope of the weld overlay shall cover the weld and the heat affected zones on each side of the weld, and shall provide for load redistribution from the item into the weld overlay and back into the item without violating applicable stress limits of NB-3200, or the Construction Code. Any laminar flaws in the weld overlay shall be evaluated in the analysis to ensure that load redistribution complies with the above.

These requirements will usually be satisfied if the weld overlay full thickness length extends axially beyond the projected flaw by at least 0 . 7 5 d ~ t where, R is the outer radius of the item and t is the nominal wall thickness of the item.

(2) Unless specifically analyzed in accordance with 2(b) (I), the end transition slope of the overlay shall not exceed 30 deg. A slope of not more than 1:3 is recommended.

(3) For determining the combined length of circumferentially-oriented flaws in the underlying base material or weld, multiple flaws shall be treated as one flaw of length equal to the sum of the lengths of the individual flaws characterized in accordance with IWA-3300.

(4) For circumferentially-oriented flaws in the underlying base material or weld, the flaws shall be assumed to be 100% through the original wall thickness of the item for the entire circumference of the item.

(5) For axial flaws in the underlying base material or weld, the flaws shall be assumed to be 100% through the original wall thickness of the item for the entire axial length of the flaw or combined flaws, as applicable for the entire circumference.

(6) For mitigative full structural overlays, the assumed flaw in the underlying base material or weld is to be based on the limiting case of the two below:

(a) 100% through wall for the entire circumference, or (b) 100% through wall for 1.5 in. (38 mm) or the combined width of the weld plus buttering, whichever is greater, in the axial direction for the entire circumference.

(7) The overlay design thickness shall be based on the measured circumference, using only the weld overlay thickness conforming to the deposit analysis requirements of I(e).

The combined wall thickness at the weld overlay, (INTENTIONALY DELETED), and the effects of any discontinuities (e.g., another weld overlay or reinforcement for a branch connection) within a distance of 2.5dRt from the toes of the weld overlay, including the flaw size assumptions defined in 2(b)(4), (5), or (6) above, shall be evaluated and shall meet the requirements of IWB-3640, IWC-3640 or IWD-3640 as applicable.

(8) The effects of any changes in applied loads, as a result of weld shrinkage from the entire overlay, on other items in the piping system (e.g., support loads and clearances,

Serial No. 07-01 16 Docket No. 50-423 Alternative Requirements Enclosure 1 Page 4 of 13 nozzle loads, changes in system flexibility and weight due to the weld overlay) shall be evaluated. Existing flaws (not in the weld overlay) previously accepted by analytical evaluation shall be evaluated in accordance with IWB-3640, IWC-3640, or IWD-3640 as applicable.

3 EXAMINATION In lieu of all other examination requirements, the examination requirements of this alternative shall be met. Nondestructive examination methods shall be in accordance with IWA-2200, except as specified herein. Nondestructive examination personnel shall be qualified in accordance with IWA-2300. Ultrasonic examination procedures and personnel shall be qualified in accordance with Appendix VIII, Supplement 11.

(a) Acceptance Examination

( I ) The weld overlay shall have a surface finish of 250 micro-in. (6.3 micrometers) RMS or better and a flatness that is sufficient to allow for adequate examination in accordance with procedures qualified per Appendix VIII. The weld overlay shall be examined to verify acceptable configuration.

(2) The weld overlay and the adjacent base material for at least % in. (13 mm) from each side of the weld shall be examined using the liquid penetrant method. The weld overlay shall satisfy the surface examination acceptance criteria for welds of the Construction Code or NB-5300. The adjacent base metal shall satisfy the surface examination acceptance criteria for base material of the Construction Code or NB -2500. If ambient temperature temper bead welding is used, the liquid penetrant examination shall be conducted at least 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> after the completed overlay has returned to ambient temperature.

(3) The acceptance examination volume, A-B-C-D, in Fig.l(a) shall be ultrasonically examined to assure adequate fusion (i.e., adequate bond) with the base metal and to detect welding flaws, such as interbead lack of fusion, inclusions, or cracks. The interface C-D shown between the overlay and the weld includes the bond and the heat affected zone from the overlay. If ambient temperature temper bead welding is used, the ultrasonic examination shall be conducted at least 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> after the completed overlay has returned to ambient temperature.

Planar flaws detected in the weld overlay acceptance examination shall meet the preservice examination standards of Table IWB-3514-2. In applying the acceptance standards to planar indications within the volume, E-F-G-H, in Fig. l(b), the thickness

" t l " shall be used as the nominal wall thickness in Table IWB-3514-2. For planar indications outside this examination volume, the nominal wall thickness shall be "t2" as shown in Fig. I(c), for volumes A-E-H-D and F-B-C-G.

Laminar flaws shall meet the following:

(a) Laminar flaws shall meet the acceptance standards of Table IWB-3514-3 with the additional limitation that the total laminar flaw shall not exceed 10% of the weld surface area and that no linear dimension of the laminar flaw area exceeds 3.0 in. (76 mm), or 10 % of the nominal pipe circumference, whichever is greater.

Serial No. 07-01 16 Docket No. 50-423 Alternative Requirements Enclosure 1 Page 5 of 13 (b) The reduction in coverage of the examination volume, A-B-C-D in Fig. l(a) due to laminar flaws shall be less than 10%. The uninspectable volume is the volume in the weld overlay underneath the laminar flaws for which coverage cannot be achieved with angle beam examination.

(c) Any uninspectable volume in the weld overlay shall be assumed to contain the largest radial planar flaw that could exist within that volume. This assumed flaw shall meet the preservice examination standards of Table IWB-3514-2, with nominal wall thickness as defined above for planar flaws. Alternately, the assumed flaw shall be evaluated and meet the requirements of IWB-3640, IWC-3640, or IWD-3640 as applicable. Both axial and circumferential planar flaws shall be assumed.

(4) After completion of all welding activities, affected restraints, supports, and snubbers shall be VT-3 visually examined to verify that design tolerances are met.

(6) Preservice lnspection (7) The examination volume in Fig. 2 shall be ultrasonically examined. The angle beam shall be directed perpendicular and parallel to the piping axis, with scanning performed in four directions, to locate and size any cracks that might have propagated into the upper 25% of the base material or into the weld overlay.

(2) The preservice examination acceptance standards of Table IWB-3514-2 shall be met for the weld overlay. In applying the acceptance standards, wall thickness, tw, shall be the thickness of the weld overlay. Cracks in the outer 25% of the base metal shall meet the design analysis requirements of 2 (b).

(3) The flaw evaluation rules of IWB-3640, IWC-3640 or, IWD-3640 shall not be applied to indications identified during preservice examination, which exceed the preservice examination standards of Table IWB-3514-2.

(c) Inservice lnspection

( I ) The weld overlay examination volume in Fig. 2 shall be added to the inspection plan and ultrasonically examined during the first or second refueling outage following application.

(2) Alternatively, for mitigative weld overlays, in which examinations are performed in accordance with 2(a)(2)(a), 3(a), and 3(b), and no inside surface connected planar flaws are discovered, the overlay may be placed directly into the population to be examined in accordance with (c)(5) below.

(3) The weld overlay examination volume in Fig. 2 shall be ultrasonically examined to determine if any new or existing cracks have propagated into the upper 25% of the base material or into the overlay. The angle beam shall be directed perpendicular and parallel to the piping axis, with scanning performed in four directions.

(4) The inservice examination acceptance standards of Table IWB-3514-2 shall be met for the weld overlay. If the acceptance criteria of Table IWB-3514-2 cannot be met, the acceptance criteria of IWB-3600, IWC-3600, or IWD-3600 as applicable shall be met for the weld overlay. Cracks in the outer 25% of the base metal shall meet the design analysis requirements of Section 2(b).

(5) Weld overlay examination volumes in Fig. 2 that show no indication of crack growth or new cracking shall be placed into a population to be examined on a sample basis.

Twenty-five percent of this population shall be examined once every 10 years.

Serial No. 07-0116 Docket No. 50-423 Alternative Requirements Enclosure 1 Page 6 of 13 (6) If inservice examinations reveal crack growth, or new cracking, which meet the acceptance criteria of IWB-3514, IWB-3600, IWC-3600, or IWD-3600 the weld overlay examination volume shall be reexamined during the first or second refueling outage following discovery of the growth or new cracking.

(7) For weld overlay examination volumes with unacceptable indications according to 3(c)(4), the weld overlay shall be removed, including the original defective weld, and the item shall be corrected by a repairheplacement activity in accordance with IWA-4000.

(d) Additional Examinations If inservice examinations reveal an unacceptable indication according to 3(c)(4), crack growth into the weld overlay design thickness, or axial crack growth beyond the specified examination volume, additional weld overlay examination volumes, equal to the number scheduled for the current inspection period, shall be examined prior to return to service. If additional unacceptable indications are found in the second sample, a total of 50% of the total population of weld overlay examination volumes shall be examined prior to operation.

If additional unacceptable indications are found, the entire remaining population of weld overlay examination volumes shall be examined prior to return to service.

4 PRESSURE TESTING A system leakage test shall be performed in accordance with IWA-5000.

5 DOCUMENTATION Use of this alternative shall be documented on Form NIS-2A.

Serial No. 07-0116 Docket No. 50-423 Alternative Requirements Enclosure 1 Page 7 of 13 a Acceptance Examination Volume A-B-C-D 112 in. (min.)

r -I

b. Thickness (ti) for Table IWB-3514-2 112 in. (min.) t- -;

c. Thickness (t2) for Table IWB-3514-2 NOTES:

(1) For axial or circumferential flaws, the axial extent of the examination volume shall extend at least % in.(l3mm) beyond the toes of the original weld.

(2) The weld includes the weld end butter, where applied.

FIG. 1 ACCEPTANCE EXAMINATION VOLUME AND THICKNESS DEFINITIONS

Serial No. 07-0116 Docket No. 50-423 Alternative Requirements Enclosure 1 Page 8 of 13 112 in. (min.)

I-i 1 112 in. (min.)

I (Note 1)

Examination Volume A-B-C-D NOTES:

(1) For axial or circumferential flaws, the axial extent of the examination volume shall extend at least % in. (13mm) beyond the as-found flaw and at least % in. (13mm) beyond the toes of the original weld.

(2) The weld includes weld end butter, where applied.

FIG. 2 PRESERVICE AND INSERVICE EXAMINATION VOLUME

Serial No. 07-01 16 Docket No. 50-423 Alternative Requirements Enclosure 1 Page 9 of 13 MANDATORY APPENDIX I AMBIENT TEMPERATURE TEMPER BEAD WELDING 1 GENERAL REQUIREMENTS (a) This appendix applies to dissimilar austenitic filler metal welds between P-No. 1, 3, 12A, 12B, and 12C1 materials and their associated welds and welds joining P-No. 8 or 43 materials to P-No. 1, 3, 12A, 12B, and 12C1 materials with the following limitation: This Appendix shall not be used to repair SA-302 Grade B material unless the material has been modified to include from 0.4% to 1.0% nickel, quenching and tempering, and application of a fine grain practice.

(b) The maximum area of an individual weld overlay based on the finished surface over the ferritic base material shall be 500 sq. in. (325,000 sq. mm).

(c) Repairlreplacement activities on a dissimilar-metal weld in accordance with this Appendix are limited to those along the fusion line of a nonferritic weld to ferritic base material on which 118 in. (3 mm), or less of nonferritic weld deposit exists above the original fusion line.

(d) If a defect penetrates into the ferritic base material, repair of the base material, using a nonferritic weld filler material, may be performed in accordance with this Appendix, provided the depth of repair in the base material does not exceed 318 in. (10mm).

(e) Prior to welding the area to be welded and a band around the area of at least 1-112 times the component thickness or 5 in. (130 mm), whichever is less, shall be at least 50F (10 C).

(f) Welding materials shall meet the Owner's requirements and the Construction Code and Cases specified in the RepairlReplacement Plan. Welding materials shall be controlled so that they are identified as acceptable until consumed.

(g) Peening may be used, except on the initial and final layers.

2 WELDING QUALIFICATIONS The welding procedures and the welding operators shall be qualified in accordance with Section IX and the requirements of 2.1 and 2.2.

2.1 Procedure Qualification (a) The base materials for the welding procedure qualification shall be of the same P-Number and Group Number, as the materials to be welded. The materials shall be postweld heat treated to at least the time and temperature that was applied to the materials being welded.

(b) The root width and included angle of the cavity in the test assembly shall be no greater than the minimum specified for the repair.

(c) The maximum interpass temperature for the first three layers of the test assembly shall be 150F (66C).

(d) The test assembly cavity depth shall be at least 1 in. (25 mm). The test assembly thickness shall be at least twice the test assembly cavity depth. The test assembly shall be large enough to permit removal of the required test specimens. The test assembly dimensions surrounding the cavity shall be at least the test assembly thickness and at least 6 in. (150 mm). The qualification test plate shall be prepared in accordance with Fig. 1-1.

(e) Ferritic base material for the procedure qualification test shall meet the impact test requirements of the Construction Code and Owner's requirements. If such requirements are not in the Construction Code and Owner's requirements, the impact properties shall be

Serial No. 07-01 16 Docket No. 50-423 Alternative Requirements Enclosure 1 Page 10 of 13 determined by Charpy V-notch impact tests of the procedure qualification base material at or below the lowest service temperature of the item to be repaired. The location and orientation of the test specimens shall be similar to those required in 2. I(f) below, but shall be in the base metal.

(f) Charpy V-notch tests of the ferritic heat-affected zone (HAZ) shall be performed at the same temperature as the base metal test of 2.1 (e) above. Number, location, and orientation of test specimens shall be as follows:

(1) The specimens shall be removed from a location as near as practical to a depth of one-half the thickness of the deposited weld metal. The coupons for HAZ impact specimens shall be taken transverse to the axis of the weld and etched to define the HAZ. The notch of the Charpy V-notch specimen shall be cut approximately normal to the material surface in such a manner as to include as much HAZ as possible in the resulting fracture. When the material thickness permits, the axis of a specimen shall be inclined to allow the root of the notch to be aligned parallel to the fusion line.

(2) If the test material is in the form of a plate or a forging, the axis of the weld shall be oriented parallel to the principal direction of rolling or forging.

(g) The Charpy V-notch test shall be performed in accordance with SA-370. Specimens shall be in accordance with SA-370, Fig. 11, Type A. The test shall consist of a set of three full-size 10 mm X 10 mm specimens. The lateral expansion, percent shear, absorbed energy, test temperature, orientation and location of all test specimens shall be reported in the Procedure Qualification Record.

(h) The average lateral expansion value of the three HAZ Charpy V-notch specimens shall be equal to or greater than the average lateral expansion value of the three unaffected base metal specimens. However, if the average lateral expansion value of the HAZ Charpy V-notch specimens is less than the average value for the unaffected base metal specimens and the procedure qualification meets all other requirements of this appendix, either of the following shall be performed:

(1) The welding procedure shall be requalified.

(2) INTENTIONALLY DELETED.

2.2 Performance Qualification Welding operators shall be qualified in accordance with Section IX.

3 WELDING PROCEDURE REQUIREMENTS The welding procedure shall include the following requirements:

(a) The weld metal shall be deposited by the automatic or machine GTAW process.

(b) Dissimilar metal welds shall be made using A-No. 8 weld metal (QW-442) for P-No. 8 to P-No. I , 3, or 12 (A, 6 , or C) weld joints or F-No. 43 weld metal (QW-432) for P-No. 8 or 43 to P-No. 1, 3, or 12 (A, 9,or C) weld joints.

(c) The area to be welded shall be buttered with a deposit of at least three layers to achieve at least 118 in. (3mm) overlay thickness with the heat input for each layer controlled to within

& l o % of that used in the procedure qualification test. The heat input of the first three layers shall not exceed 45kJlin. (1.8 kJ/mm) under any conditions. Particular care shall be taken in the placement of the weld layers of the austenitic overlay filler material at the toe of the overlay to ensure that the HAZ and ferritic base metal are tempered. Subsequent layers

Serial No. 07-01 16 Docket No. 50-423 Alternative Requirements Enclosure 1 Page 11 of 13 shall be deposited with a heat input not exceeding that used for layers beyond the third layer in the procedure qualification.

(d) The maximum interpass temperature for field applications shall be 350°F (180°C) for all weld layers regardless of the interpass temperature used during qualification. The interpass temperature limitation of QW-406.3 need not be applied.

(e) The interpass temperature shall be determined by:

(I) Temperature measurement (e.g. pyrometers, temperature indicating crayons, thermocouples) during welding. When it is impractical to use interpass temperature measurements described in this paragraph due to situations where the weldment area is not accessible, such as internal bore welding or when there are extenuating radiological concerns, either paragraph 3(e)(2) or paragraph 3(e)(3) may be used.

(2) Heat flow calculations using the variables listed below as a minimum:

(i) welding heat input (ii) initial base material temperature (iii) configuration, thickness, and mass of the item being welded (iv) thermal conductivity and diffusivity of the materials being welded (v) arc time per weld pass and delay time between each pass (vi) arc time to complete the weld (3) Measurement of the maximum interpass temperature on a test coupon that is equal to or less than the thickness of the item to be welded. The maximum heat input of the welding procedure shall be used in the welding of the test coupon.

(0 Particular care shall be given to ensure that the weld region is free of all potential sources of hydrogen. The surfaces to be welded, filler metal and shielding gas shall be suitably controlled.

Serial No. 07-0116 Docket No. 50-423 Alternative Requirements Enclosure 1 Page 12 of 13 Discard Reduced Secfion Tensile Discard I L I t I 1 I I GENERAL NOTE: Base metal Charpy impact specimens are not shown.

FIG. 1-1 QUALIFICATION TEST PLATE

Serial No. 07-01 16 Docket No. 50-423 Alternative Requirements Enclosure 1 Page 13 of 13 TABLE 1 REFERENCES FOR ALTERNATIVE EDITIONS AND ADDENDA OF SECTION XI 2001 Edition with 1995 Edition 1995 Edition with 1989 Edition 1986 Edition with 2003 Addenda with 1996 1995Addenda with 1991 1988 Addenda through 2004 Addenda Addenda through 1989 Edition with through 2001 through 1995 Edition with 1990 2006Addenda Edition with Edition Addenda 2002 Addenda IWA-4000 IWA-4000 IWA-4000 IWA-4000 IWA-4000 & IWA-RepairIReplacement 7000 Activities IWA-4311 IWA -431 1 IWA -431 1 NA Configuration Changes IWA-4410 Welding, IWA 4410 IWA 4410 IWA 4170 IWA 4120 Brazing, Metal Removal, and Installation - General Requirements IWA-3300 Flaw IWA-3300 IWA-3300 IWA-3300 Characterization IWA-4611 Defect IWA-4611 IWA-4421 & IWA-4170(b) IWA-4120 Removal IWA-4424 IWB-3514 Standards IWB-3514 IWB-3514 IWB-3514 IWB-3514 for Category B-F IWBICID -3600 IWBIC-3600 IWBIC-3600 IWBIC-3600 IWBIC-3600 Analytical Evaluation IWB/C/D-3640 IWBIC-3640 or IWBIC-3640 or IWBIC-3640 or IWBIC-3640 Evaluation IWBIC-3650 IWBIC-3650 IWBIC-3650*

Procedures

• Starting with the 1989 Edition with the 1989 Addenda I